<!DOCTYPE html>
<html>
<head>
    <meta charset="UTF-8">
    <title>数独分享封面</title>
    <style>
        * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
        }

        .share-cover {
            width: 500px;
            height: 400px;
            background: linear-gradient(135deg, #EEF6FF 0%, #F8FAFC 100%);
            display: flex;
            flex-direction: column;
            align-items: center;
            justify-content: center;
            padding: 20px;
            font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
        }

        .sudoku-board {
            width: 240px; /* 增加尺寸 */
            height: 240px;
            background: white;
            border-radius: 12px; /* 增加圆角 */
            box-shadow: 0 8px 24px rgba(74, 144, 226, 0.12); /* 优化阴影效果 */
            display: grid;
            grid-template-columns: repeat(3, 1fr);
            gap: 3px; /* 增加间距 */
            padding: 3px;
            margin-bottom: 32px;
            position: relative;
        }

        .sudoku-cell {
            background: white;
            border: 1.5px solid #E8F0FE; /* 优化边框 */
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 32px; /* 增大字号 */
            color: #1A2B3C; /* 更深的文字颜色 */
            font-weight: 600;
            transition: all 0.3s ease;
        }

        .sudoku-cell:hover {
            background: #F5F9FF;
        }

        .pencil {
            position: absolute;
            right: -50px;
            top: 50%;
            transform: translateY(-50%) rotate(-45deg); /* 添加旋转效果 */
            font-size: 40px;
            filter: drop-shadow(2px 2px 4px rgba(245, 166, 35, 0.2)); /* 添加投影 */
        }

        .title {
            font-size: 36px;
            color: #1A2B3C;
            font-weight: bold;
            margin-bottom: 12px;
            letter-spacing: 2px; /* 增加字间距 */
        }

        .subtitle {
            font-size: 18px;
            color: #4A90E2;
            opacity: 0.9;
            letter-spacing: 1px;
            position: relative;
        }

        .subtitle::after {
            content: '';
            position: absolute;
            bottom: -8px;
            left: 50%;
            transform: translateX(-50%);
            width: 40px;
            height: 3px;
            background: #4A90E2;
            border-radius: 2px;
            opacity: 0.3;
        }

        /* 添加装饰性元素 */
        .decoration {
            position: absolute;
            width: 100%;
            height: 100%;
            pointer-events: none;
        }

        .dot {
            position: absolute;
            width: 6px;
            height: 6px;
            border-radius: 50%;
            background: #4A90E2;
            opacity: 0.1;
        }

        .dot:nth-child(1) { top: 10%; left: 15%; }
        .dot:nth-child(2) { top: 20%; right: 20%; }
        .dot:nth-child(3) { bottom: 15%; left: 25%; }
        .dot:nth-child(4) { bottom: 25%; right: 15%; }
    </style>
</head>
<body>
    <div class="share-cover">
        <!-- 装饰性圆点 -->
        <div class="decoration">
            <div class="dot"></div>
            <div class="dot"></div>
            <div class="dot"></div>
            <div class="dot"></div>
        </div>

        <div class="sudoku-board">
            <div class="sudoku-cell">7</div>
            <div class="sudoku-cell">1</div>
            <div class="sudoku-cell"></div>
            <div class="sudoku-cell"></div>
            <div class="sudoku-cell">4</div>
            <div class="sudoku-cell">2</div>
            <div class="sudoku-cell">5</div>
            <div class="sudoku-cell"></div>
            <div class="sudoku-cell">9</div>
            
            <div class="pencil">✏️</div>
        </div>

        <h1 class="title">数独挑战</h1>
        <p class="subtitle">提升思维 · 享受乐趣</p>
    </div>
</body>
</html>